The steamy weather that hit Perth at the weekend is likely to settle in.
Though temperatures will be marginally cooler than at Christmas and new year, the Weather Bureau says that unsettled conditions will mean high humidity.
"A ridge developing in the Great Australian Bight and a trough off the west coast today will bring warm temperatures and north-easterly winds," forecaster John Grimes said.
"There's a decent chance of showers and thunderstorms but that generally means it gets fairly humid."
Temperatures are forecast to fall to 31C by midweek.
Warmer weather is predicted at the weekend, with 32C and the risk of a storm tipped for Saturday and 30C and the chance of a storm on Sunday.
In NSW, firefighters urged rural residents to prepare their homes against the threat of bushfires as about 70 blazes continue to burn across the State.
NSW Rural Fire Service spokesman Ben Shepherd said that firefighters were trying to get as many of the fires under control as possible before conditions turned nasty tomorrow when it was expected to be hot and dry.